Graphene-superconducting-graphene nanostructures for electron focusing

Abstract Graphene has proven to be a promising candidate for nanotechnological applications, in particular, design Veselago's lenses where the use of pn interfaces could allow to focus electrons without need for magnetic fields. These lenses can study in graphene-superconducting-graphene structures, where it is possible to focus electrons in electrons or electrons in holes. In this work, we study how tuning the Fermi energy or using imperfect interfaces affects the focusing of electrons or holes allowing to realize conditions that favor hole focusing over electron focusing.